JP2001224082A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption in a system for automatic metering or the like. SOLUTION: Slave units connected to gas meters or the like and desired to call are grouped into a plurality of groups limit the time within a prescribed time (times t1, t3, etc.), from a call until end of reply thereby ensuring the time for an interruption transmission/reception signal (times t2, t4, etc.). Limiting the number of slave units in an operating state to the number of slave units of a group can suppress power consumption of the slave units.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system such as an automatic meter reader for a gas meter.

[0002]

2. Description of the Related Art Conventionally, in order to perform automatic meter reading of a gas meter or the like, a wireless slave unit is attached to each gas meter or the like, connected to a center via a wireless master unit, and communication is performed between the slave unit and the center. . Conventionally, as shown in FIG. 7, even when it is desired to call a plurality of slave units, for example, the wireless master unit has to call the slave units one by one.

When calling the slave unit 5-1, the center 1 sends a slave unit calling signal to the wireless master unit 3 (step 701), and the wireless master unit 3 transmits a calling signal to the slave unit (step 70).
2), all the slave units receive the signal (step 703), and only the slave unit 5-1 having the same calling ID code operates to respond to the wireless master unit 3 (step 704); Responds to the center 1 (step 705).

Next, also when calling the slave unit 5-2, the center 1 sends a slave unit calling signal to the wireless master unit 3 (step 70).
6), the wireless master device 3 transmits a calling signal to the slave device (step 707), and all the slave devices receive the signal (step 70).
8) Only the child unit 5-2 having the same calling ID code operates and responds to the radio cell station 3 (step 709), and the radio cell station 3 responds to the center 1 (step 710).

[0005]

As described above, in the conventional system shown in FIG. 7, the wireless master unit has a large number of transmissions, and the battery is quickly consumed when it is driven by a battery.

The present invention has been made in view of such a problem, and an object of the present invention is to reduce the power consumption of a system such as an automatic meter reading system (both a wireless master unit and a slave unit).

[0007]

According to a first aspect of the present invention, in a system in which a center and a plurality of terminal devices are connected, the terminal devices are divided into a plurality of groups. A communication system characterized in that when a terminal device is called from a center, the calling is performed sequentially for each group.

According to a second aspect of the present invention, in a system in which a center and a plurality of terminal devices are connected, the terminal devices are divided into a plurality of groups, each terminal device is simultaneously called from the center, and This is a communication system characterized by providing a time difference and responding in order.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a communication system A according to an embodiment of the present invention. The center 1 and a plurality of wireless master units 3 (only one is shown in FIG. 1) are connected by a public line 9. Handsets 5-1 to 5-n such as PHSs are attached to the meters 7-1 to 7-n, respectively.
Automatic meter reading of 1 to 7-n and a command from the center 1 (for example, a gas emergency shutoff command) are transmitted to the slave unit 5 through the wireless base unit 3.
1 to 5-n transmit and receive.

The slave units 5-1 to 5-n are referred to as terminal units for convenience. The wireless master device 3 is a station such as a PHS installed on a street or the like, for example.

In the present invention, the slave unit 5 communicating with the wireless master unit 3
-1 to 5-n are divided into m groups. In FIG. 1, the slave units 5-1 to 5-4 are the slave unit first group, and the slave units 5-5.
5-8 are divided into the child device second group,. As will be described later, the number of slave units constituting one group is selected so that the time from when the entire group is called up to the end of the sequential response is equal to or less than a predetermined time.

Next, the procedure of the handset calling operation according to the first embodiment of the present invention will be described with reference to FIGS. FIG.
FIG. 9 is a timing chart of a slave unit call. FIG.
FIG. 6 is a flowchart for calling a slave unit according to the first embodiment. FIGS. 2 and 3 show that the center 1 has a total number of slave units (slave unit 5).
-1 to 5-n) to perform automatic meter reading.

First, the center 1 calls the slave unit first group (slave units 5-1 to 5-4) (step 201), and the wireless master unit 3 calls the call signal including the call ID of the slave unit first group. Is transmitted (step 202, step 301 in FIG. 3). Handsets 5-1 to 5-4 with matching call IDs
Is called to enter the operating state (step 203, step 302 in FIG. 3). Since the intermittent operation timing of the child device before being called varies, the timing at which the child device is called and enters the operation state also varies.

Next, the slave units 5-1 to 5-
4 responds to the wireless master devices 3 one by one (steps 204 to 207, step 303 in FIG. 3). For example, at this time, the slave unit transmits a meter reading value of the meter and the like. Wireless base unit 3
Transmits the contents of the response of the slave unit to the center 1 (step 208).

The time t1 from calling one slave unit group (step 201) to obtaining a response (step 208) is set to be equal to or less than the allowable communication delay time of emergency communication (for example, 1 minute and 30 seconds). Adjust the number of slave units that make up the unit group. After the handset response (step 208), if there is no emergency communication (NO in step 304 in FIG. 3), the standby time t
After 2 seconds, the next slave unit second group (slave units 5-5 to 5-8) is called (step 209, step 301 in FIG. 3).

Similarly, after the response from the second group of the slave units is completed (step 216), if there is an emergency communication instruction (YES in step 304 in FIG. 3), the emergency communication instruction is transmitted from the center 1 to the wireless master unit 3 (step 216). In step 217), an emergency call is made to the slave units 5-1 to 5-n (steps 218 and 219, step 305 in FIG. 3).

After the emergency call, if there is a handset group to be called continuously, the calling operation is repeated (step 220, NO in step 306 in FIG. 3).

In the present invention, as shown in FIG. 4, the center 1 and the centralized meter reading board 13 are connected by a public line 11, and the meters 7-1 to 7 are connected from the centralized meter reading board 13 using a bus wiring 15.
It can also be used in the communication system B to which -n is connected. That is, the meters 7-1 to 7-n are divided into a plurality of groups, called up for each group to obtain a response, and time for emergency communication is secured. In this case, the meter 7-
1 to 7-n are referred to as terminal devices.

As described above, according to the present embodiment, when it is desired to call all of the slave units (slave units 5-1 to 5-n), the slave units are divided into groups, and from the calling of one group to the response. By setting the time (t1, t3...) To be equal to or less than the allowable communication delay time for emergency communication and providing the time t2, t4... For emergency communication, the response to emergency communication can be improved. Furthermore, the time during which each of the called slaves is in the operating state can be shortened, so that there is an effect of suppressing the power consumption of the slaves.

Next, a second embodiment of the present invention will be described with reference to FIGS. The configuration of the communication system is the same as that shown in FIG. 1, and sub-units 5-1 to 5-n are divided into sub-unit groups m. FIG. 5 is a timing chart of calling the slave unit, and FIG. 6 is a flowchart of calling the slave unit, assuming that the center 1 calls the slave units 5-1 to 5-8 and performs automatic meter reading of the meter. is there.

First, the center 1 calls the first and second slave units (slave units 5-1 to 5-8) collectively (step 501), and the wireless master unit 3 sends the first and second groups of slave units. Is transmitted (step 502, step 601 in FIG. 6). First, of the slave units 5-1 to 5-8 whose call IDs match (step 50).
3) First, the slave units 5-1 to 5-4 in the first group enter the operating state (step 602 in FIG. 6). Then, the slave units 5-5 to 5-8 in the second group start operation with a time difference so that the slave units in the first group end the response and enter the operation state after the elapse of the emergency communication time zone t52. The time is set (step 603 in FIG. 6).

Next, the slave units 5-1 to 5-4 of the first group which have entered the operating state respond to the wireless master unit 3 one by one (steps 504 to 507, step 60 in FIG. 6).
4). For example, at this time, the slave unit transmits a meter reading value of the meter and the like. Wireless master device 3 transmits the contents of the response of the slave device to center 1 (step 508).

In the same manner as in the first embodiment, until the responses of all the slaves in the first group are obtained (steps 504 to 5).
The time t51 of 08) is set within the allowable communication delay time of emergency communication (for example, 1 minute and 30 seconds), and the number of child devices constituting the child device group is adjusted. Handset response (step 508)
Thereafter, if there is emergency communication (step 509, YES in step 605 in FIG. 6), emergency communication is performed (step 60 in FIG. 6).
6) If not (NO in step 605 in FIG. 6), after the standby time t52, the second group of slave units (slave units 5-5 to 5-5-
8) enters the operating state, and sequentially goes to the wireless master device 3 (step 5).
10-513), and further responds to the center 1 (step 514, step 607 in FIG. 6).

Steps 602 and 60 in FIG.
3 or between steps 603 and 604, emergency communication from the center 1 can be performed.

According to the second embodiment, for example, even when it is desired to call all the slave units (slave units 5-1 to 5-n), the number of times that the center 1 and the wireless master unit 3 call the slave units is as follows. One time. That is, the slave units are divided into groups, and a time difference is provided in the operation start timing of each called slave unit group, so that a time for emergency communication is secured in the gap time t52 of the operation start timing. It is to be noted that the times t51, t53,... To which the slave unit group responds are adjusted to be equal to or less than the allowable communication delay time of emergency communication (for example, 1 minute 30 seconds), and the number of slave units configured in the slave unit group is adjusted.

Therefore, the response to the emergency communication can be improved, and the power consumption of the slave unit and the power consumption of the wireless master unit 3 can be suppressed. It should be noted that the second embodiment is also similar to FIG.
Can be applied to the communication system B using the bus wiring 15 shown in FIG.

In each of the embodiments described above, the communication system for performing the automatic meter reading has been described. However, the present invention is not limited to such a system for performing the automatic meter reading, but a plurality of terminals are connected to the center. It can be widely used for a system in which a center performs center polling and collects data from a plurality of terminals.

[0028]

As described above in detail, according to the present invention, it is possible to suppress the power consumption of a system such as an automatic meter reading (both the wireless master unit and the slave unit).

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a communication system A according to an embodiment of the present invention.

FIG. 2 is a diagram showing a communication sequence according to the first invention.

FIG. 3 is a flowchart of a sequence in FIG. 2;

FIG. 4 is a configuration diagram of a communication system B according to the embodiment of the present invention.

FIG. 5 is a diagram showing a communication sequence according to the second invention.

FIG. 6 is a flowchart of a second sequence.

FIG. 7 is a diagram showing a communication sequence of a conventional slave unit call.

[Explanation of symbols]

 A: Communication system B: Communication system 1: Center 3: Wireless base unit 5-1 to 5-n Slave unit 7-1 to 7-n Meter 9.・ Wireless network 11 ・ ・ ・ Circuit network 13 ・ ・ ・ Central meter reading board 15 ・ ・ ・ Bus wiring

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04M 11/00 301 H04B 7/26 X F term (Reference) 5K048 AA16 BA36 CA03 CA08 DA02 DC01 DC07 EA11 EB01 EB02 EB10 FB08 FC01 HA01 HA02 HA05 HA07 5K067 AA43 BB21 5K101 KK12 LL01 LL03 LL11 MM07 RR12 RR16 SS07 TT06 UU05 UU16

Claims (10)

[Claims] In a system in which a center and a plurality of terminal devices are connected, the terminal devices are divided into a plurality of groups, and when the center calls the terminal devices, the terminal devices are sequentially called for each group. Communication system. 2. The communication system according to claim 1, wherein the center performs emergency communication after calling one group and then calling another group. 3. The method according to claim 1, wherein the center sets the number of terminal devices belonging to the group so that the time from when a certain group is called to when all the terminal devices belonging to the group responds is shorter than a predetermined time. The communication system according to claim 1, wherein: 4. The communication system according to claim 3, wherein said predetermined time is an allowable communication delay time of emergency communication. 5. In a system in which a center and a plurality of terminal devices are connected, the terminal device is divided into a plurality of groups, each terminal device is simultaneously called from the center, and a time difference is provided for each group. A communication system that responds in order. 6. The communication system according to claim 5, wherein the emergency communication is performed after a certain group responds and before another group responds. 7. The communication system according to claim 5, wherein the number of terminal devices belonging to the group is set such that the time required for all terminal devices belonging to a certain group to respond is shorter than a predetermined time. 8. The communication system according to claim 5, wherein the predetermined time is an allowable communication delay time of emergency communication. 9. The communication system according to claim 1, wherein the communication system is an automatic meter reading system, and the terminal device is a slave unit connected to a meter. 10. The communication system according to claim 9, wherein said meter is one of a gas meter, an electric meter, and a water meter.